Atrophy of the residual alveolar ridge following tooth loss in an historical population

Oral Diseases (2010) 17 , 33–44 Objectives: To study the natural aetiopathology of jaw atrophy after tooth loss, unaltered by prosthetic procedures, an historical population without modern dental treatment was examined. Methods: Based on the hypothesis that there are predictable changes in shape during jaw‐atrophy, frequency and degree of atrophy as well as clinical aspects of bone quality and resorption were determined in the skeletal remains of 263 individuals. The potential association between age and frequency/severity of atrophy was analysed. Results: Atrophy in at least one jaw segment was present in 45.2% of the analysed jaw specimens. The residual ridge underwent a series of changes in shape and height following the pattern of resorption described for modern populations. The severity of these alterations was associated with the age of the individual and the region within the jaw. Atrophy was frequently related to structural degradation of the covering cortical layer. Conclusions: These findings prove that atrophy of the jaw evidently does occur, displaying similar patterns of resorption in a population without modern prosthetics, where the negative effect of ill‐fitting dentures is excluded. The basic information about alterations of shape and the cortical layer covering the residual crest might help to provide a deeper insight into aetiopathological mechanisms of this common oral disease.     

Interaction between anandamide and sphingosine-1-phosphate in mediating vasorelaxation in rat coronary artery

Background and purpose:

This study establishes a pharmacokinetic/pharmacodynamic (PK/PD) model to describe the time course and in vivo mechanisms of action of the antinociceptive effects of lumiracoxib, evaluated by the thermal hyperalgesia test in rats.

Experimental approach:

Female Wistar fasted rats were injected s.c. with saline or carrageenan in the right hind paw, followed by either 0, 1, 3, 10 or 30 mg·kg⁻¹ of oral lumiracoxib at the time of carrageenan injection (experiment I), or 0, 10 or 30 mg·kg⁻¹ oral lumiracoxib at 4 h after carrageenan injection (experiment II). Antihyperalgesic responses were measured as latency time (LT) to a thermal stimulus. PK/PD modelling of the antinociceptive response was performed using the population approach with NONMEM VI.

Results:

A two-compartment model described the plasma disposition. A first-order model, including lag time and decreased relative bioavailability as a function of the dose, described the absorption process. The response model was: LT=LT₀/(1 +MED). LT₀ is the baseline response, and MED represents the level of inflammatory mediators. The time course of MED was assumed to be equivalent to the predicted profile of COX-2 activity and was modelled according to an indirect response model with a time variant synthesis rate. Drug effects were described as a reversible inhibition of the COX-2 activity. The in vivo estimate of the dissociation equilibrium constant of the COX-2-lumiracoxib complex was 0.24 µg·mL⁻¹.

Conclusions:

The model developed appropriately described the time course of pharmacological responses to lumiracoxib, in terms of its mechanism of action and pharmacokinetics.     

A founder mutation in BBS2 is responsible for Bardet‐Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders

Innes AM, Boycott KM, Puffenberger EG, Redl D, MacDonald IM, Chudley AE, Beaulieu C, Perrier R, Gillan T, Wade A, Parboosingh JS. A founder mutation in BBS2 is responsible for Bardet‐Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders. Bardet‐Biedl syndrome (BBS) is a multisystem genetically heterogeneous disorder, the clinical features of which are largely the consequence of ciliary dysfunction. BBS is typically inherited in an autosomal recessive fashion, and mutations in at least 14 genes have been identified. Here, we report the identification of a founder mutation in the BBS2 gene as the cause for the increased incidence of this developmental disorder in the Hutterite population. To ascertain the Hutterite BBS locus, we performed a genome‐wide single nucleotide polymorphism (SNP) analysis on a single patient and his three unaffected siblings from a Hutterite family. The analysis identified two large SNP blocks that were homozygous in the patient but not in his unaffected siblings, one of these regions contained the BBS2 gene. Sequence analysis and subsequent RNA studies identified and confirmed a novel splice site mutation, c.472‐2A>G, in BBS2. This mutation was also found in homozygous form in three subsequently studied Hutterite BBS patients from two different leuts, confirming that this is a founder mutation in the Hutterite population. Further studies are required to determine the frequency of this mutation and its role, if any, in the expression of other ciliopathies in this population.     

OUR EXPERIENCE WITH DIAGNOSTIC AND THERAPEUTIC CHOLEDOCHOSCOPY

Flexible choledochoscope was used in 16 patients undergoing common bile duct (CBD) exploration for suspected stones. Stones were found in the CBD in 4 patients in whom introperative cholangiogram was normal. T-tube cholangiogram done between the 10th and 14th postoperative days was normal in all 16 patients. None of the patients had symptoms suggestive of retained stones during follow-up ranging from 6 to 19 months. We feel that the use of choledochoscopy in patients undergoing CBD exploration will help reduce the incidence of retained stones.KEY WORDS: Cholangiography, Choledocholithiasis, Choledochoscopy     

HIV INFECTION IN HERPES ZOSTER

The interaction of Herpes zoster and Human Immunodeficiency Virus (HIV) was evaluated in 120 cases of herpes zoster admitted to our hospital and in 157 HIV positive cases detected in the hospital during the same period. The incidence of HIV seropositivity was 22.5 per cent in cases of herpes zoster without AIDS defining disease conditions. Whereas the incidence of Herpes zoster in cases detected to be HIV positive in the same period was 17.2 per cent. A large number of herpes zoster cases found to be HIV positive were in the sexually active age group viz. 21-30 years. Thoracic dermatomal segments were most frequently involved. None of the cases had severe complications or showed evidence of progression to symptomatic HIV disease.KEY WORDS: Herpes zoster, HIV infection     

Human milk as a carrier of biochemical messages

Not only does breast milk provides an ideal nutrient composition for the newborn, but it also contains a variety of substances that may actively influence growth and development of the infant and stimulate neonatal protection against gastrointestinal diseases. Hormones, growth factors, cytokines and even whole cells are present in breast milk and act to establish biochemical and immunological communication between mother and child. In addition, milk nutrients such as nucleotides, glutamine and lactoferrin have been shown to influence gastrointestinal development and host defense. The unique properties of milk as a mediator of biochemical messages will be presented and the clinical significance of breastfeeding in the prevention of neonatal gastrointestinal diseases will be discussed.     

Role of oestrogen therapy in the management of short stature in Turner syndrome

It is now clear that parenteral growth hormone (GH) therapy stimulates growth and increases the adult stature of girls with Turner syndrome. In addition, oestrogens are given to almost all girls with this syndrome because of primary hypogonadism. Oestrogens influence both growth and maturation of the epiphyseal growth plates. Therefore, the form and timing of oestrogen therapy may have an important impact on the outcome of other growth-promoting therapies. To examine the impact of the timing of oestrogen initiation on growth, a randomized trial was conducted in patients with Turner syndrome who were receiving GH. Some patients received oestrogen at 12 years of age, while in others this treatment was not started until 15 years of age. Those girls that received oestrogen later were significantly taller as adults. The single most important factor in determining height gain appeared to be the number of years of GH therapy prior to the initiation of oestrogen treatment.